Is it okay to use "gotcha" in daily life? Or is it only used toward boss?
Great question. "Gotcha" is actually a slang form. It has a few uses in casual conversation. You can use it to mean "I have got you" when you surprise or frighten someone, or to show that you have an advantage over them. It can also be used as an exclamation to mean "got you" when you have caught someone or something. And, finally, it can be used to mean that you understand what someone is saying, like "I understand". Which is how it is being used in this clip, Monica is letting Chandler know she understands his request. Ex: Gotcha! Scared you didn't I. Ex: Gotcha, you little thief. Ex: Gotcha, that's easy to do.